<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <!--引入Vue-->
  <script type="text/javascript" src="../js/vue.js"></script>
  <title>数据代理</title>
</head>
<body>
  <div id="root">
  </div>

  <script type="text/javascript">
    let obj={x:100}
    let obj2={y:200}

    Object.defineProperty(obj2,'x',{
      get(){
        return obj.x
      },
      set(value){
        obj.x=value
      }
    })
  </script>
</body>
</html>